Mr Biondo said that there were no recent figures available on the national impact of the drugs, and that usage levels varied greatly between states.

He told a Victorian Parliamentary inquiry that the rehabilitation sector was being overwhelmed by the demand for services from methamphetamine users, who need more care than people addicted to other drugs.

"There is a longer start-up time, and then there's a longer period of time to actually work through the issues that individuals have got," Mr Biondo said.

"The government needs to engage with the treatment sector in terms of what the experts are saying and to allocate appropriate levels of funding and resourcing."